Exemplary embodiments relate generally to a semiconductor device and an operating method thereof and more particularly to reducing a load of bit lines when the semiconductor device is operated.
A semiconductor device includes a plurality of memory blocks in which data can be stored. The plurality of memory blocks form a plane, and a memory cell array of the semiconductor memory device may consist of a single plane or multiple planes. The memory cell array consisting of the single plane is called a single plane type, and the memory cell array consisting of the multiple planes is called a multi-plane type. With the growing demands for high-capacity memory devices, the multi-plane type is being applied to many memory devices. The planes have the same configuration, and thus one of the planes is described in detail below.
FIG. 1 is a diagram illustrating a known memory cell array.
Referring to FIG. 1, a plane 10 includes a plurality of memory blocks (e.g., first to kth memory blocks). Each of the first to kth memory blocks includes a plurality of cell strings (not shown) coupled between bit lines BL and a common source line. The cell strings have the same configuration, and thus one of the cell strings is described in detail below. The cell string includes a drain select transistor, memory cells, and a source select transistor which are coupled in series. The drain select transistor is coupled to the bit line BL, and the source select transistor is coupled to the common source line.
Each bit line BL shares different memory blocks. More specifically, the first cell string of the first memory block, the first cell string of the second memory block, the first cell string of the third memory block and the first cell string of the kth memory block are coupled to a common bit line. That is, cell strings, included in different memory blocks but having the same order, are coupled to the common bit lines BL. For this reason, the bit lines BL are extended so as to be coupled to the first to kth memory blocks. Accordingly, when any selected memory block is operated, there also exists a load LD of the bit lines related to the remaining unselected memory blocks other than the selected memory block. The program operation of the first memory block is described below as an example.
A program permission voltage having a ground voltage level is supplied to bit lines selected from among the bit lines coupled to the first memory block, and a program inhibition voltage having a power source voltage level is supplied to the remaining unselected bit lines. Here, the voltages of the unselected bit lines shared by the first to kth memory blocks must be raised to the program inhibition voltage. Therefore, a load LD corresponding to the total length of the bit lines shared by the first to kth memory blocks may cause difficulties in raising the voltages of the unselected bit lines to the program inhibition voltage. That is, as the load LD of the bit lines increases, current consumption may increase when the bit lines are precharged, the time taken to raise the voltages of the bit lines to a target level may increase, and the time taken to lower the voltages of the bit lines to a target level when the bit lines are discharged may also increase. Furthermore, in a read or verify operation, reliability of read data may be deteriorated because it becomes difficult to precisely detect the voltages of the bit line according to an increase of the load LD of the bit lines.